Optimal duration of treatment in surgical patients with calf venous thrombosis involving one or more veins.

The aim of this study was to evaluate different durations of treatment in patients with calf venous thrombosis (CVT) involving 1 or more deep veins. The authors studied 2 groups of patients with postsurgical CVT diagnosed by echo-color Doppler. The first group consisted of 68 patients with CVT involving a single vein, and the second group consisted of 124 patients with CVT involving 2 or more veins. Immediately after diagnosis, all patients were treated with nadroparin calcium and sodium warfarin. Heparin treatment was withdrawn after 5-6 days of treatment, when the international normalized ratio (INR) was stabilized between 2 and 3. Each group was divided into 2 subgroups receiving anticoagulation treatment for 6 or 12 weeks, respectively. The endpoint was proximal extension of the thrombotic lesion, defined as the extension of the thrombus to the popliteal and/or femoral vein. In patients with single-vessel CVT there was no significant difference between the 2 subgroups, whereas in patients with CVT involving 2 or more vessels, a statistically significant difference was observed, the number of cases showing proximal extension of the thrombus being higher among patients treated for 6 weeks. Twelve weeks of anticoagulation treatment is better than 6 weeks only in patients with postsurgical CVT involving 2 or more veins.